


Love is the Burden and the Song

by shealynn88



Category: Supernatural
Genre: AU after 10.18, Angst with a Happy Ending, Concerned Sam, Happy Ending, M/M, MoC Dean Winchester, MoC violence
Language: English
Status: Completed
Published: 2019-09-30
Updated: 2019-09-30
Packaged: 2020-11-07 21:37:59
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,347
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20824208
Author URL: https://archiveofourown.org/users/shealynn88/pseuds/shealynn88
Summary: Castiel knows that love is sacrifice, and he will give anything to help Dean fight the Mark of Cain.AU after 10.18





	Love is the Burden and the Song

**Author's Note:**

  * For [Seralina](https://archiveofourown.org/users/Seralina/gifts).

> Seralina requested a fic based on the poem "Love Me Little, Love Me Long." Here you are, I hope you like it!!

_What is love?” Castiel asks._

_“It is fear and obedience,” Raphael tells him. It is why we follow, and God leads.”_

_“But, human love...the kind they have for each other...”_

_Raphael smiles, a thin smile that never reaches his eyes. “It is a tool. Just that. It makes them act without thinking—amenable to God’s will. Angels are better than that.”_

  


Castiel finds Dean alone in the kitchen after dinner. Charlie and Sam are chatting animatedly in the bunker library, and Dean is staring into the mirror over the sink like he doesn’t know what’s looking back.

“I think you should give it to me,” Castiel says, finally. 

Dean turns, whiskey in hand, and raises an eyebrow. “You’re not gonna wine and dine me, first?”

“The Mark, Dean.”

Dean’s face goes smooth and stubborn. “That’s a stupid idea.”

“At least hear me out,” Castiel says calmly. He’d expected the resistance. “Now that I have my Grace back, I’m strong, I think they’ll cancel—”

“Right,” Dean cuts him off. “You’re strong. With the Mark, you’ll be stronger. But not, like, fluffy-bunny strong, more like, kill-everything-that-moves strong.” He steps forward and Castiel holds. “I’m dangerous and I’m _human_. You’d be the T2 version of that time you played God. No.”

“My Grace and the Mark will cancel each other out. I won’t be as powerful anymore, but I also won’t have the urge to kill that you have—”

“Based on _what_, exactly? What did you find that Sam and Charlie, with the entire Men of Letters library, haven’t?”

Anger rises slowly like the tide, and Castiel clenches his jaw. “What did I _find?_ I’ve been here for millenia. I’ve been part of countless skirmishes over artifacts and I’ve seen millions of spells and I know how these things work. It’s a curse, correct? Well, Grace is a miracle. I’m not offering this lightly, Dean. It’s a conclusion based on experience. Is _that_ good enough for you?”

“No, it’s not.” Dean steps up and prods his chest with an index finger. "Know why? I know _you_. If you're not up for it, we have a whole new mess on our hands.”

“And what do we have now?” Castiel cuts back. He takes a deep breath. He’s not here to fight with Dean. Or the Mark. “Dean. This will buy us time.”

“No, it’ll buy us a bloodbath. Cas, I _have_ a plan. You’re my plan. When this goes to hell, and you and I both know it will, you’re going to kill me. _That’s_ the plan. That’s it. That’s what I’m headed for and I’m all right with it.”

“Well, I’m not.” The reasons are endless, but he sticks to something Dean might care about. “I’m not even sure that’s an option. The Mark is very invested in keeping you alive.”

“Listen, Cas. If Sam set you on this, tell him he’s barking up the wrong tree. I’ll find a way to end this, but it ends _here_, and it ends with _me_.”

Dean stalks past him and up the hallways to the bedrooms. The conversation is clearly over.

  


_What is love?” Castiel asks._

_“A fucking fairy tale,” Dean says stiffly, refusing to look up._

_A moment goes by, the buzzing of the lamp outside filling the air._

_He’s just turning to leave when Dean says quietly, “Sacrifice.”_

  


It's been three weeks, and everyone can see that Dean is losing ground against the Mark. Three weeks, and he's holding everything too tightly, his jaw is perpetually clenched, and his fingers are always in motion on his glass or the table. He still won't entertain Castiel's proposal. 

Castiel sits down across from him and watches him watch the fireplace. Almost like there’s nothing wrong. Like they aren’t both broken open and freshly scarred. 

Castiel touches his pocket nervously. 

“I want to know what you look like on the inside,” Dean says conversationally, taking a sip from his ever-present tumbler.

Even with his limited understanding of metaphor, Castiel is fairly certain he means it literally.

“I’d rather you didn’t,” he says without rancor. He wonders what will make a difference. What will make Dean see. 

There’s an odd sort of itch that makes him want to be honest. Without planning, without guile. As if it would change things. As if Dean could be honest with him.

But that’s not even the issue, really. Because Dean isn’t honest with himself. He lives by brushing past inconveniences like feelings and fears and realities. He lives in his own sort of bubble of muscling through, of looking out for everyone else and ignoring the fact that his destruction will have consequences. That it will break Sam into pieces. That Castiel will become something else if he lives through it.

He doesn’t plan to.

The battle he’s fighting now is a new one, but it's part of the same war—the war for Dean. This is not a battle Castiel can afford to lose, and he’s about to put it all in Dean’s hands. Dean, who has always been dark and stubborn, who is now influenced by an evil Castiel can’t properly comprehend.

But it’s still Dean, so there has to be hope.

“Is it the same for angels? The same…” Dean purses his lips, spins his index finger in a lazy circle in front of him, pointed at the table. “Circle jerk of need, want, take? Is it really anything more than an eternal game of King of the Mountain?”

Cas takes a deep breath. “Is this you or the Mark talking?”

“Is there a difference, Cas? Really?” Dean looks up and his eyes are narrow with pain and fury, and Castiel has seen this before—how the two are basically the same in him. They’re lit from the same fuel. They share the same space and the same words and the same expression.

“I don’t know. I knew you before. I think I know you now.” He holds out his hand and Dean extends his slowly, suspiciously, and Cas unbuttons the cuff of his shirt with care before rolling it up and sliding his fingers over Dean’s arm, over the Mark.

Dean hisses when his fingers meet it and Castiel feels the muscles tighten.

“Do you need to feed it?” Cas asks. He wonders how many kills, how many blackout rages are left in the Mark before he loses Dean to the darkness again.

Dean flinches. “It’s always hungry.”

Cas meets his eyes and Dean looks away.

"I'm fine,” Dean says. It lacks conviction.

“Do you think it’s changed you?” He still sees Dean underneath it. He wonders if Dean can see it, too.

“I think it’s...encouraging me. I think it’s just...found what it likes and made it stronger.” He looks up and he’s scared, Castiel can see it there, behind the rest of it, the bitterness and the bravado. “It hasn’t made anything up, you know. I hurt people. It’s what I do. It’s what I’ve always done.”

Castiel strokes over the Mark absently, feels Dean’s self-loathing down to his bones. There are questions on his tongue, questions of whispers, of darkness, of what is a hunger for power and what is just a nest of secret desires. Castiel knows about that. He knows how power can make you drunk and foolish, how it can make you feel invincible.

“It feels good, doesn’t it?”

Dean’s lip lifts in a snarl and he jerks his arm out of Castiel’s grip before he gets it under control. When he’s still again, Castiel covers the mark with one hand. Gently.

“Yeah. It does.” Dean says it like he’s throwing down a gauntlet.

“It felt good when I took the souls,” Cas tells him quietly. “It felt like I could do anything. I could finally change the world. Make it better.”

Dean shakes his head. “You came back. There’s no way back from this.” He pulls his arm back and rolls the sleeve down. “Why are you here, Cas?” He sounds angry, but Castiel can hear the pain underneath. Dig hard enough, and it’s all pain down there.

Castiel feels his body tense and forces himself to relax. “Dean, you must know.”

Dean looks at him, steely. “I want to kill you right now.” He reaches out and grabs Castiel’s face in a mockery of a caress. His thumb is just inside Castiel’s jaw and he presses there, until Castiel makes a sound of pain. “I want to rip your throat out.”

“Not you,” Castiel says. He doesn’t pull away. “That.” He gestures at the Mark. “I’m here because you need me here. _I_ need to be here. You have to know I’ll do anything I can.” 

“Like that time you tried to kill me over the souls you took?”

“It was an unfortunate lapse,” Castiel admits. “The effects of the souls of Purgatory were unexpected. Much like the effects of the Mark.”

“So, what, I should forgive you?”

Castiel smiles. Dean’s grasping, now. “You already have. You should forgive _yourself_. And...Dean.” It might be too soon. Dean is still angry. But there’s so little time left and he’ll need to get used to the idea. It has to be now. “Please. Let me help you.”

Dean narrows his eyes and his jaw goes firm. “I already told you…”

He trails off when Castiel takes the vial out of his pocket and opens his hand slowly.

Dean scrambles back, stumbling over his chair. “What...what the hell is _that_? Shit, Cas, is that _yours_?”

“Yes.”

“What the _fuck_? You just got it back!”

“Yes, and then I took it out,” he says patiently. He allows himself to glance at the Grace swirling in the vial. It’s not his. Not anymore.

“Well, put it back!”

“I’m not going to do that.” He meets Dean’s eyes and refuses to look away.

“Well, I’m not taking it. What the fuck would I do with it anyhow?”

“You can take it into your blood. It will fight the Mark.”

“No. Damn it, Cas, _no!_ What the fuck were you thinking?” He paces around the table and Castiel stands up to meet him. Dean steps forward and Castiel steps back until he can’t anymore. Until the wall is at his back. 

Dean keeps coming. Shoves him into the cement. “I don’t get the happy ending, okay? That’s Sam’s. Coulda been yours if you weren’t so damn excited to throw yourself on a sword. You have no _idea_ what I am, now. How deep this thing goes. Know what we want, now?” he snarls, gesturing at the Mark.

Castiel forces himself to take a deep breath. “I won’t fight you, Dean.”

Dean makes an animal sound and slams his hand against the wall next to Castiel’s head. Once. Twice. Castiel touches him gently, palm to Dean’s chest. It’s only shaking slightly. His vessel—his _body_—feels incredibly fragile in the face of Dean’s outburst. “Please,” he says softly. “You’ll hurt yourself.”

Dean snarls at him, eyes wild, and then grabs his shoulder too tightly and throws him to the ground. Pain explodes through his hip when he collides with the edge of a chair and by the time he’s back on his feet, Dean is nowhere to be found.

He twists his body gingerly. It’s hard to know, but he doesn’t think anything is broken. 

“That went well,” he mutters, limping back to the guest room.

  


_“What is love?” Castiel asks._

_Sam’s expression softens. “It’s...knowing someone, and having them know you, even the dark things. The hard things. All that, and they still want to be with you. They still see the good things in you.”_

_“You’ve been in love?”_

_“Yeah.” He gets a far away look. A sad, gentle smile. “You don’t always get to keep it.”_

_“Is it worth it?”_

_Sam’s mouth twists and he swallows hard. “Every single minute.”_

  


“What the hell were you thinking?” Sam spluttered.

“Funny, that’s what your brother said.”

“Well, he’s right about that! We’re all worried, man, but...your _Grace!_ This is just trading one problem for another. Look, I want him back, too, but it’s not worth it. Not this.”

“_Sam._ We have to be focused. Strategic. The problem to solve right now is your brother. Or, what he’s going to become if we don’t do something. At least, it was until you brought a witch into this.” He sighs, glancing at Rowena where she sits, cuffed, near the stairs. 

Rowena gives him a razor smile and waves dismissively. “Oh, please. Don’t mind me, I’m just waiting to see who wins this thrilling exchange of wit.” 

Castiel pointedly turns his back on her. “It’s the best chance we have. We just need to convince him to _use_ it.”

“Right. That’s all. Dean, the most stubborn person on the planet, just needs to be convinced to take your Grace, rendering you mortal and putting you in danger. Great idea.”

“He’s not _taking_ it, Sam. The damage is done, I’ve already extracted it.”

“Well, I doubt he sees it that way—he’s messed up, but he still cares about you. We’ll find another way.”

“This will buy us time. Time during which he can think clearly. When he can work _with_ us.”

“Cas, no, it’s too _much_.” His hands curl into fists and he shakes his head. “_God_, you’re both _idiots!_”

“Sam, I really think—”

A new voice cuts the conversation short. Dark and confident. “Well, well. What do we have here?”

Castiel turns, Sam by his side, to see Dean stroll into the dungeon. He’s wearing a wide grin that looks like death, and Castiel feels an unfamiliar tightness in his gut. 

Fear, he realizes. Bone-chilling fear. He’s frozen in place.

“You found me a witch.” He steps down the stairs, slowly, swaggering. “And it’s not even my birthday.”

“Dean,” Sam soothes, “She can help—”

“Sam, shut the fuck up. She wouldn’t help us if we were the last door to paradise. She’s a snake, and you...Jesus Christ, how are you all so fucking stupid? You think saving me is worth unleashing _this?_”

He strides over to Rowena and strikes, hard enough that she falls and doesn’t say a word.

Castiel reacts, finally, because Dean is on the knife’s edge of turning. He can see it in the way Dean moves, smooth and easy, like he’s hunting a monster instead of beating a chained woman to death. 

“Not so big now, are you, bitch?” Dean jeers, hitting her twice more before Castiel can get there, and then he’s grappling, holding Dean’s arm and losing the fight before it’s begun. Sam is moving behind him, but it’s clear that it’s too late. Dean is too powerful—too strong and too far gone. There is nothing Castiel can do.

Dean turns on him, face twisted into a feral grimace, close enough that Castiel can see the black encroaching on his irises.

There’s a quick movement to the side and Castiel feels something sharp and then a cold agony slides between his ribs. He realizes, too late (always too late), there is one more thing he can do.

He can die.

Dean’s face looms over his as he chokes on his own blood, and the black bleeds away as quickly as it came. Dean looks suddenly human. Horrified and broken. He cradles Castiel’s face in his hands. “Cas?” he gasps.

“Dean,” he whispers. This, right here. This must be heartbreak. He thought he’d have more time. He thought _they’d_ have more time. He takes a careful, rasping breath. “It’s not...your fault, okay?” His field of vision is swimming with little lights. “It’s alright,” he reassures.

The last thing he hears is Dean screaming his name.

  


_What is love?” Castiel asks._

_Anna smiles, and she radiates compassion. “It’s...divinity. It’s impossible to explain. It makes you smaller. It blows you apart and expands you into a galaxy. It’s the best reason to be human.” She leans in and whispers to him. “It’s close enough to touch, Castiel. If you’re brave. If you want it.”_

  


He expects to wake up in Heaven. Or Hell. He can see the case for either. But a bed in the bunker is...unexpected.

He barely has a chance to attempt to sit up before Dean is there with a hand on his chest. “Easy, buddy,” he says softly. “Give it a minute.”

“Dean! What...what happened?”

Dean lets out a bitter bark of a laugh. “What happened. Well, you got your way, you dramatic bitch. Hell of a way to go about it.” Dean’s jaw gets tight and his nose flares, the way it does when he’s in pain. The way it does when Sam is hurt and hasn’t yet woken up.

“You almost died,” he says through clamped teeth. He won’t look Castiel in the eye. “I almost _killed_ you.”

Castiel takes a tentative breath into pristine lungs. “You healed me.”

“I tried to give you your Grace back.”

“You can’t, I cut it off.”

“Yeah, well...we figured that out. Asshole.”

Castiel laughs cautiously. He anticipates pain but it never comes. “You’re okay?”

Dean growls, then sighs. “It seems...better, now. Hurt like hell when it went in. I think they went ten rounds in my spleen, but, uh. Yeah. I don’t have the cravings like I did. And, hey, I’m basically an X-men, now. X-man? Whatever.” He laughs weakly.

Castiel smiles. “You did well. It feels like everything is where it’s supposed to be.” 

Dean's face is tight with pain. He wraps fingers around Castiel’s forearm slowly, with uncharacteristic gentleness. “Cas?”

The hand is warm, and desperately tight, and for some reason that makes Castiel’s chest seize. There’s something thick in his throat that he can barely get words past. “Dean.”

“You’re an idiot. Don’t do that again, okay?” His voice breaks and he clears his throat. “I don’t really want to do this without you.” 

Castiel keeps his voice soft. “If you make me choose, it will always be you.” It’s been true since the moment he pulled Dean from Hell, but he’s never been as sure of it as he is now.

“Don’t say that. Please don’t. You know I’m not worth it.”

“You are to me,” Castiel says softly. That thick feeling in his throat is like a dam waiting to burst.

“Please don’t,” Dean says, voice rough and pleading. “Not ever. Not for me.” His head falls, and his forehead touches Castiel’s, and the touch is electric and warm and something blossoms in Castiel’s chest. Something more. Something like wildflowers and summer days, and all the things he thought he could never have, but was broken enough to want anyway.

He reaches a hand up, slides it against Dean’s neck, against the bristle soft hairs there. Dean takes a breath and holds it and Castiel’s heart gallops.

“Yes,” he promises. “For you.”

_“Cas…”_

Dean is closer. It’s more gravity than anything, as far as Castiel can tell. Dean’s nose slides alongside his, and he feels warm breath against his lips, and there’s a prickling sensation moving over his limbs and into his torso and lower, and lower, and, yes, he recognizes it, now. Like what he felt with April. Like that, but more. Not just skin deep, not just curling in his abdomen, but growing and exploding in his chest, in his head, in his fingers against Dean’s neck, curling tighter now, and pulling lightly. _Yes_, he wants to say, but he’s forgotten the words.

Dean’s lips meet his and it’s clear Dean knows how to say everything that needs to be said. This is _his_ language, built on breath and the gentle touch of lips and tongues and soft sounds that are almost sobs but also the purest joy.

“Cas,” Dean murmurs against his lips.

Castiel takes Dean’s face in his hands, which have ached for this for longer than he’s known what that ache meant. 

“Yes,” he says, finally finding words again.

  


_“What is love?” Castiel asks._

_“This,” Dean tells him, hand splayed over his human heart. “You.”_


End file.
